Sorry, one more hint that might help to find a right way. The first what appeared in BEYOND were PangoScript commands. After that we spent some time on OSC servers. During this process appeared gateway between commands and OSC. After that appeared ability to operate with Objects. It allow read and write the state of various objects in BEYOND. And, then we made a gateway between Objects and OSC. After that development of OSC stopped, because... we have gateways now. No need to duplicate the code at our side, same as it hopefully help at your side. So, please remember that we have /b/ and /beyond/general/

OK, it is possible do what you did, it is legal and valid. But it does not explain why /beyond/general/playtimeline does not work. Could you please send me screenshot of OSC monitor as you did above? Address /beyond/general/playtimeline works, try to run it from PangoScript editor. There should be some other detail.